This invention relates to a cutting instrument for a root canal filler used in dental treatment. More particularly, it is concerned with a root canal filler cutting instrument of a construction such that on the upper surface of a base portion are formed slots in which root canal fillers are to be fitted, the root canal fillers being held in place by an inner pressing surface of a cover plate which is attached to the base portion so as to facilitate the cutting operation for the root canal fillers, and the slots being graduated to facilitate the dimensioning of the root canal fillers to be cut.
If the hard tissue of a tooth is decalcified due to a decayed condition of the tooth and the decay becomes worse until it reaches the dental pulp, the latter will inflame and result in pain. To treat the tooth decayed to such an extent the dental pulp is extracted and thereafter a root canal filler is inserted up to the apica in an air-tight manner. The treatment which follows extraction of the dental pulp is generally called root canal treatment. If the decayed tooth is left as it is without receiving the above-mentioned treatment, the dental pulp will finally lose its life and consequently the pain will be allayed, but thereafter the dental pulp will develop into an infected root canal, which usually results in the formation of a diseased condition at the apica. The treatment at this stage is specially called infected root canal treatment, in which the interior of the root canal is cleaned mechanically and chemically followed by root canal filling. Thus, the root canal filling is the basis of clinical dentistry. Unless the root canal filling is made correctly, a dead space will be formed within the root canal and the peripheral tissue of the apica will be damaged; and in the worst case it may lead to the extraction of the tooth, and thus the clinical progress after treatment is seriously influenced. Root canal filling materials used at present are metallic or semi-hardened fillers having thicknesses standardized in conformity with root canal treating utensils. But the operation for adjusting a root canal filler into a desired length, namely the length of root canal (usually operation length) is very troublesome. Specially, the molar tooth portion usually has three canals, so when root canal fillers of different lengths and thicknesses must be provided at the same time, the operation has heretofore been very troublesome. In view of such circumstances there has been a demand for providing, in a short time, root canal fillers of required thicknesses and lengths calculated from the time of root canal treatment which precedes the root canal filling, to thereby improve the treatment efficiency and the accuracy of root canal filling.
This invention can almost satisfy the above-mentioned demand.